Houston, Jul 12 (IANS): The Electric Reliability Council of Texas (ERCOT) has asked residents and businesses to reduce their power use as the heat index exceeded 27.77 degrees celsius in about half of the south central US state.

As of Monday afternoon, the ERCOT website twice forecast large losses of generation though it said no rolling blackouts were expected this week, Xinhua news agency reported.

At 2 p.m. Monday Central Time, the regulator, which manages 90 per cent of the state's power grid, shifted from "normal conditions" to "conservation alert, please reduce power use" as the load reached 76,499 megawatt.

The ERCOT forecast demand in Texas to peak at 79,671 megawatt, just short of the 80,168 megawatt that will be available. It warned that if demand spiked more than forecast, there would be "no market solution".

Thermostats should be turned up at least one degree Fahrenheit, and major appliances should not be used from 2 to 8 p.m. Monday Central time, according to the alert.

The alert is one step before Energy Emergency Level 1, which would allow the regulator to tap electricity from other grids nearby when reserves are dangerously low, local media reported. If the situation worsens, ERCOT can order transmission companies to cut off power to industrial customers and residential consumers.

This heatwave began more than a week ago and is still going strong, challenging the state's power grid. The near-record temperatures in much of Texas have forced various outdoor events to be either delayed or cancelled over safety concerns.

It's Texas' fourth heat wave of the season, a hot streak that started impacting Texans way before the official start of summer, said a CNN report.

"I can say that so far, we have been having one of our hottest summers on record," John Neilson-Gammon, a state climatologist, told CNN.